PEORIA, Ariz. -- Pitchers and catchers reported to the Padres' Spring Training complex Wednesday afternoon, marking the first day of a "wide open" rotation competition in the eyes of skipper Andy Green.
With the first formal workout slated for Thursday, Green sized up his starting candidates, essentially dividing the race into three tiers.
"Clayton Richard is in the rotation," said Green. "And we move forward with the expectation that we acquired Bryan Mitchell to put him in the rotation. [Luis] Perdomo, [Dinelson] Lamet probably have legs up on other guys. Everybody else is fighting."
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When the Padres signed Richard to a two-year extension last September, they assured him of a starting job. Mitchell, meanwhile, has been viewed as a long-term rotation piece since San Diego acquired him in a trade with the Yankees.
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That duo comprises the first tier, with Perdomo and Lamet making up the second, though Green made a point to say nothing is guaranteed for the two youngsters this spring.
Tier 3 is where things get interesting. Colin Rea, Robbie Erlin and Matt Strahm have all recovered from surgeries that prevented them from pitching for San Diego in 2017. They're all healthy and threw bullpen sessions Tuesday after reporting early.
Erlin and Rea have fully recovered from Tommy John surgeries, while Strahm had knee surgery last July to repair a torn patellar tendon. Strahm, who will be limited during fielding drills early in camp, could just as easily win a place in the bullpen. But, for now, he's squarely in the starting mix.

"We're going to move forward that way because it's always easier to abort mission and go the other direction," Green said. "It's tough to get a guy ready as a reliever, then turn him into a starter. ... He's right on the line."
Green made a point to mention Tyson Ross, who signed a Minor League deal during the offseason. Ross has battled injuries over the past two years, and the Padres skipper noted that Tuesday's bullpen session was "the first time I've ever seen his arm move freely in a Padres uniform."
Jordan Lyles and Christopher Young also signed during the offseason, giving the club about eight options for three spots.
"Depth is huge," said catcher Austin Hedges. "It'll be awesome just to see guys compete. That's what [Spring Training] is about."
Backup catcher a mystery
It's still possible the Padres add a backup catcher to the mix this spring, with Rocky Gale and Raffy Lopez currently set to compete for playing time behind Hedges.
The front office is actively weighing its options, and any addition would likely be a non-roster candidate with big league experience.
In any case, both Gale and Lopez will be given every chance to win that job. The Padres are high on Lopez, who signed a Minor League deal after hitting .288/.370/.563 between Double-A and Triple-A last season. They're impressed with the recent swing changes Lopez made, which allowed him to smack 20 homers between the Minors and the Majors for Toronto.

Gale, meanwhile, was a career Minor Leaguer before his callup last year. He's been lauded for his work with the club's Minor League pitchers, and he launched his first career home run last September.
Gale turns 30 next week and is in camp in Peoria for the ninth year in a row. This spring undoubtedly marks his best chance to win an Opening Day roster spot.

"I've felt like that every year, coming into Spring Training, that I'm competing for a spot," Gale said. "That stuff doesn't really change. You're fighting for your career every single day. It's the same approach."
Shortstop help coming?
Green noted that the Padres are having "ongoing discussions" about the possibility of adding another backup shortstop candidate, though a signing isn't imminent or even considered a necessity.
San Diego added Freddy Galvis in a December trade with the Phillies, and he will receive the bulk of the playing time in 2018. Currently, Dusty Coleman projects as Galvis' backup, with the other shortstop options in camp -- Luis Urias, Javier Guerra, Allen Cordoba and Fernando Tatis Jr. -- all in need of more Minor League seasoning.
The club would prefer to add another player of Coleman's ilk to the mix -- a utility-type option on a non-roster invite.